I purchased a yg bracelet that was advertised as 22k. It has a stamp 750 which is for 18k gold. However it has another stamp. I’m getting mixed information regarding what the other stamp means. Anyone has any idea ? Also, if the piece has 2 different stamps ( assuming a mix of 2 different metals), how would one know what % is what ?seems like the stamp is 834 ( see pics). Thank you